#include <stdio.h>

struct student{
    char num[10];
    char name[8];
    int score[3];
    float ave;
} stu[5];

int main(){
    int i,j,sum;
    FILE *fp;
    for(i=0;i<5;i++){
        printf("\ninput score of student %d:\n",i+1);
        printf("NO:");
        scanf("%s",stu[i].num);
        printf("name:");
        scanf("%s",stu[i].name);
        sum=0;
        for(j=0;j<3;j++){
            printf("score %d:",j+1);
            scanf("%d",&stu[i].score[j]);
            sum=sum+stu[i].score[j];
        }
        stu[i].ave=sum/3.0;
    }

    fp=fopen("a.txt","w");
    for(i=0;i<5;i++){
        if(fwrite(&stu[i],sizeof(struct student),1,fp)){
            printf("\n%s,%s,%d,%d,%d,%6.2f\n",stu[i].num,stu[i].name,stu[i].score[0],stu[i].score[1],stu[i].score[2],stu[i].ave);
        }
    }
    return 0;
}